Neon John wrote:
> It took the longest time to figure out which rockbox to use. Nowhere in the
> docs or on the box does it say whether this is a recorder or player. Further
> confusing the issue is the existence of a "line in" jack.

It's a player. For some reason they changed the name of the Player model
to Studio.

> Which brings me to the purpose of this post. What IS the purpose of a "line
> in" jack on a player?

It has virtually no use at all. You can mix the MP3 audio with the audio
from the Line In jack, that's all.